diff --git a/rubygem-pg.spec b/rubygem-pg.spec
index 67b0248..6255fef 100644
--- a/rubygem-pg.spec
+++ b/rubygem-pg.spec
@@ -8,7 +8,7 @@
 Summary: A Ruby interface to the PostgreSQL RDBMS
 Name: rubygem-%{gemname}
 Version: 0.11.0
-Release: 4%{?dist}
+Release: 5%{?dist}
 Group: Development/Languages
 # Upstream license clarification (https://bitbucket.org/ged/ruby-pg/issue/72/)
 #
@@ -47,8 +47,9 @@ Documentation for %{name}
 %prep
 %setup -q -c -T
 mkdir -p .%{gemdir}
+export CONFIGURE_ARGS="--with-cflags='%{optflags}'"
 gem install --local --install-dir .%{gemdir} \
-            --force %{SOURCE0}
+            -V --force %{SOURCE0}
 
 %build
 
@@ -106,6 +107,9 @@ popd
 
 
 %changelog
+* Fri Jun 03 2011 Vít Ondruch <vondruch@redhat.com> - 0.11.0-5
+- Pass CFLAGS to extconf.rb.
+
 * Fri Jun 03 2011 Vít Ondruch <vondruch@redhat.com> - 0.11.0-4
 - Binary extension moved into ruby_sitearch dir.
 - -doc subpackage made architecture independent.